<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="box"></div>
</body>
<script>
    let arr = ({a:4,b:8,c:6},8,0,[5,1])
    console.log(arr);    //[5,1]
    let arr3 = (1+2,3,4+6)
    console.log(arr3);   //10

</script>
</html>
<style>
    .box{
        width: 100px;
        height:100px;
        background: skyblue;
        position: absolute;
    }
    .box{
        left:50%;
        top:50%;
        margin-left:-50px;
        margin-top:-50px;
    }
    /* .box{
        left:50%;
        top:50%;
        transform: translate(-50%+100px,50%);
    } */

</style>